This invention relates in general to vehicle wheels and in particular to a one piece cast vehicle wheel having a lightener pocket formed beneath the outboard tire bead seat and an apparatus and process for casting the one piece wheel.
It is known in the art to cast one piece wheels from an alloy of a light weight metal, such as, for example, an alloy of aluminum, magnesium or titanium. Conventional highly automated and high volume casting machines can be used to gravity cast such wheels. Such machines typically include a rotatable carousel which carries a plurality of multi-piece wheel molds. As the carousel is indexed, each wheel mold is sequentially rotated toward a charging station. Upon reaching the charging station, molten metal is poured into the mold. As the carousel continues to be indexed, the metal cools to form a wheel casting. Once the metal is completely solidified, the mold is opened and the wheel casting removed. Risers and gates are removed from the casting and the casting is machined to a final shape.
A typical cast wheel includes a generally cylindrical wheel rim which is adapted to carry a pneumatic vehicle tire. The rim has a recessed center portion which is called a deepwell. Extending from the deepwell toward the inboard end of the wheel is a tapered portion called a leg. The leg terminates in a circumferential inboard tire safety bead which retains an inboard tire wall bead upon the wheel rim. Adjacent to the inboard tire safety bead is an inboard tire bead seat which carries the inboard tire wall bead. The inboard end of the wheel rim terminates in an inboard tire retaining flange.
The outboard end of the deepwell ends at a deepwell wall which extends radially to a circumferential outboard tire safety bead which retains an outboard tire wall bead upon the wheel rim. Adjacent to the outboard tire safety bead is an outboard tire bead seat which carries the outboard tire wall bead. The outboard end of the wheel rim terminates in an outboard tire retaining flange.
The wheel further includes a circular wheel disc which is typically formed across the outboard end of the wheel rim to provide a sufficient volume within the wheel to receive the larger disc brake assemblies used on current cars and steering and drive components which are included in front wheel drive vehicles. The wheel disc typically includes a central wheel hub which is supported within the wheel rim by plurality of wheel spokes. A pilot hole is formed through the center of the wheel hub and a plurality of wheel lug holes are formed through the wheel hub on a bolt-circle which is concentric with the pilot hole. The outboard end of the wheel rim supports the wheel spokes and is commonly referred to as a wheel sidewall.
Alternately, a wheel spider comprising a wheel hub and a plurality of spokes can be formed within the wheel rim.